Currently optical fiber illumination elements such as element 12 shown in FIG. 1 are used exclusively in medical illumination where small packaging is critical. Although the cost of raw glass or plastic fiber is relatively inexpensive, the cost of assembling the fiber into an endoscope tube or other surgical device may be high. Once the fiber is inserted, it generally must be glued and polished to a specific angle. Optical fiber is also extremely fragile and brittle. During the assembly process or in the field after many sterilization cycles, optical fiber and other conventional waveguide plastics may start to break down and degrade. Color change is also very common with fiber optics after many sterilization cycles. Since the fiber is integrated into a medical tool, any damage to the fiber optics also results in damage to the tool, thus causing an expensive overhaul. The relatively small size of the distal end of an illumination fiber also makes obscuration by blood or other material in a surgical site very likely and thus hinders to efficient surgery.
Another significant challenge in many conventionally illuminated procedures is cable management. There may be many cables typically present in the sterile field: camera cable, fiber optic cable, irrigation and suction, etc. Since the optical fiber cable has the largest diameter it typically is the heaviest cable. One of the challenges that face surgeons using illuminated tools is constant rotation of the illuminated tool to view different orientation angles. When an illuminated tool is rotated, the fiber optic cable is forced to rotate around with the tool, thus causing interference. These issues become even more important during arthroscopic surgery. Since the optical fiber cable is heavy, it will actually rotate the endoscope, often forcing the surgeon to keep one of their hands on the fiber optic cable to prevent unwanted spinning of the endoscope.
The illumination fiber also occupies space inside an illuminated tool, an endoscope or other surgical implement. By allocating space to optical fiber illumination, the diameter of optics may be limited to maintain the smallest overall tool size.
Typical coupling surfaces to a fiber optic cable are circular, mainly because the fiber cable itself is made with circularly bundled fibers. The problem is accounting for the various sizes of fiber bundles (e.g., 3.0 mm, 3.5 mm, 4 mm, 5 mm diameter bundles are common) to which a light conducting or light guiding device, also called a waveguide device, may be coupled in order to optimize coupling efficiency. Light that is not coupled from the fiber into the waveguide is lost light that cannot be used for illumination. In addition, this lost light may have infrared components that contribute to heating of the coupling connectors, which are typically metal in fiber optic cables. This heating may be significant enough to cause minor to major burns.